创建 FastMCP 实例

Time to build for real! The Python SDK gives you FastMCP, a friendly class that turns plain functions into a working MCP server. 🚀

Everything starts with one import. You pull FastMCP from the official package so the rest of your file has it ready to use.

Now you make a server instance. Calling FastMCP(...) hands you back one object that will hold every tool you add later.

That first string is your server's name. Clients show it to users, so pick something clear like "weather" or "notes" instead of "app1".

That mcp variable is the hub of your whole server. You attach tools, resources, and prompts to it, then ask it to run.

FastMCP is fast because it hides the protocol plumbing. You write normal Python, and it generates the JSON-RPC schemas behind the scenes.

Believe it or not, these two lines are already a valid server skeleton. It just has no tools yet, so it can't do anything useful so far.

You can pass extra hints too. Some setups accept an instructions string that tells clients what the server is for at a glance.

A common pattern is one module holding a single mcp instance. It keeps each server small, focused, and easy to reason about.

Try to keep your server name stable over time. Clients and configs reference it, so renaming later means updating every place that points at it.

Creating the instance does not start a server. It just builds the object in memory; starting it is a separate step you'll meet soon.

Let's lock in what the constructor argument does.

You imported FastMCP, created an mcp instance, and gave it a clear name. That object is the hub every capability will hang off. Next: a real tool! 🎉